Phenotypic and genetic analysis of milk fatty acids in UK Holstein-Fresian cows

Abstract

Applying calibration equations to mid-infrared (MIR) spectrometry has been shown to be an efficient method to predict fatty acid composition in bovine milk. Milk fatty acids were predicted from monthly milk MIR for approx. 30,000 cows with between 3 – 7 months of milk tests per animal. Results on approx. 60,000 test records showed that milk fatty acids varied with stage of lactation and time of year. Univariate linear sire models (repeated) were used to estimate heritabilities for a selection of the predicted fatty acids with heritabilities ranging from 0.09 – 0.33. The research demonstrates the practical application of this technique in the UK dairy herd and used to estimate genetic parameters and therefore has the potential to deliver genetic improvement tools for fatty acids routinely.